Some guys in the Tarantula community were wondering about the processor limits we can expect running some of the latest marlin features together such as linear advance, s-curve, junction deviation, and bed skew.

The Tarantula uses a MKS Sbase 1.2-1.4. My first question is if the Atmega 2560 is 8 bit. What makes this board 32bit? The delta little monster uses a MKS Gen and it does pretty well but a lot of people upgrade to the duet so im assuming the obvious here...

Our question is basically the CPU load we are going to get if we turn on all these features, if we even can. Can anyone give me some guidance? It would be cool if we could actually get a real time CPU read out in marlin and see(anyone know of such a thing?)

Quoteo_lampe
My best guess is, the sd-card readout is the bottleneck, not the CPU. The Duet uses the hardware port for SD-card, not sure about Smoothie or it's clones...

The Smoothieboard and clones use SPI access to the SD card, same as the 8-bit boards. Only the Duets use fast 4-bit parallel access to the SD card. However, even with SPI access the speed of reading the SD card during printing shouldn't be a bottleneck. The main benefit of fast SD card access is that it allows high speed file uploads to the SD card over the network.

BTW there is also an experimental port of RepRapFirmware for LPC1769 boards, see [forums.reprap.org].